Apparatus for the manufacture of artificial stone.



' No. 702,523." Patented lune l7, I902. F; MARX.

APPARATUS FOR THE MANUFACTURE OF ABTIFIGIAL STONE.

(Application filed May 17, 1901.)

v zzvezizfon n: Noam: PETERS co momurna, \msummon n c tion in theaccompanying drawing'.

UNITED- STATES] PATENT GFFICE.

FRIEDRICH MARX, OF LEIPSIC, GERMANY.

APPARATUS FOR THE MANUFACTURE OF ARTIFICIAL STONE.

SPECIFICATION forming partof Letters Patent N 0. 702,573, dated June 17,1902.

Application filed May 17, 1901. Serial No. 60,788. (No model.)

T0 alt whom it may concern.-

Be 1t known that I, FRIEDRICH MARX, manufacturer, a subject of theKingof Saxony, and

a resident of No. 28 Berlinerstrasse, Lei psic, in the Kingdom of Saxonyand Empire of Germany, have-inventedce'rtain newand useful Improvementsin Apparatus for the Manufacture of Artificial Stone, of whichthe'following is a specification.

This invention relates to an apparatus for .the manufacture ofartificial stone free from pores and unassailable by moisture or atmospheric influences and which'does not break or shrink and on account ofits dense and uniform consistency is particularly adapted for use forlithographic purposes, as it is'at least quite equal and 'incertainrespects superior to natural lithographic stones.

An apparatus for thejfmanufacture of artificial stone of thisdescription is shown in sec- The same consists, essentially, of a mixingdevice a in the form of a cylinder which can be closed hermetically.Above the cylinder is arranged a funnel I), under which is an opening 0in the cylinder for the introduction of the material. 7 Upon theopposite side to this opening 0 is another opening in the cylinder,leading to the union d, which can be closed by a stop-cock. Within thecylinder are the mixing-balls for mixing and further grinding of thealready-ground materiahjwhile above this union is a guardor sieve e' toprevent the falling out ofthe said balls duringthe discharge of theliquid mass. Above this mixing device is a vessel f, which is soconnected to the mixing-drum a as to be easilydetached and which servesto receive a lye of magn'esium chlorid for' the purpose of saturatingthe ground material in-the'mixing-d-rum."

This lye must beconducted from the vessel f to the mixing-drum a throughthe said connecting-tube g without air being carried with the liquid.

Beneath the mixing-drum Ct is a mold-box for the reception of'thematerial, and in conformity with the entire manufacture of the stone,which takesplace ifl'oacuo, the said material must reach the mold-box inmono. To efiect this, the said mold-box is arranged in a casing 72,which can be closed hermetically by means of a cover 2' and Which beingmounted on rails can easily be moved away in a lateral direction. Atelescopic and movable pipe is attached tothe cover t for the purposeofeffecting an air-tight connection betweeuthe mixing-drum a and thecasing 71,

thesaid'pipe lo 'being arranged'to'slide into the union d and attachedat that end. The

form'ot marble or, if the consistency and quality of thefi'nishedpr'oductare not of very great moment, in the form of limestone,with an addition of burnt magnesite in a. proportion corresponding tothe desired quality and hardness of the'stone; further, two parts offinely-pulverized burnt magnesite and two parts of puremagnesium-chlorid lye of 25 to 30 Baum. varied within certain limits.

This mixture can, however, be Commercial chlorid of magnesium cannot beused for this 1 process without further preparation, but itself or itsconcentrated solution must be sub- 'mitted to a purifying process.jplished by simply submitting the solution for ten to twelve days to theatmospheric air, whereby the'i'mpurities, particularly sodium This'isaccomchlorid, magnesium sulfate, ahdjother. salts, crystallizeout,jwhile clay and organicsubstances deposit on the bottom. Bythisoperation alladmixtures, amounting to about ten per cent. of the rawmaterial, are separated and the remaining solution of chlorid ofmagnesium can be considered as chemically pure. With the'aid of thematerial thus purified artificial stones can be produced which ofier aperfect resistance against the influence of air and do not undergo inthe course of time any change in their form. Moreover, such stones showsuch a uniformstructure that they can easily be polishedandused aslithographic stone, in 'whichcase theyhave many advantages over naturallithographic stones. If no great resistance toiweather and durability isrequired, unpurified or only slightly-purified materials can be used.

The manufacturing process is here as follows: The desired quantity ofafinely-ground mixture in suitable proportions of calcium carbonate andmagnesite is introduced. through the funnel b and the opening 0 into thedrum a, whereupon after hermetically closing the drum the connection ismade between the latter and the injector, so that on the operation ofthe latter a vacuum is produced in the drum corresponding to a column ofwater of about thirteen feet. Hereby the air is drawn out of the poresof the powdered mixture, and consequently on moistening the powder themoisture will force its way into the pores, thereby preventing theformation of empty spaces or fissures in the finished stone. The supplyof chlorid of magnesium solution acting as moistening means from thereceiverf is effected by connecting the latter with the drum through theconnecting-pipe Whereupon after opening the stop-cocks the solution willbe drawn into the drum, and after disconnecting the pipe 9 an intimatemixture of the contents is effected by revolving the drum. If required,the drum can be exhausted once more to remove any traces of air from themixture. The connection between the drum and the casing h is theneffected by attaching the connecting-pipe 7a to the union d, the saidcasing containing the mold I and being hermetically closed by the cover'1'. Upon effecting a connection by a branch pipe to the injector m avacuum is also produced in the casing corresponding to a column of waterof about twenty-three feet; but in any case it should exceed the vacuumin the drum. The descent of the contents of the drum into the mold-frameZ takes place automatically after opening the stop-cocks in the union dand the connecting-pipe 7c. The very fluid and uniform mass completelydeprived of air spreads out in the mold-box l, which after detaching therespective connecting means and opening the cover 1' can be lifted outand then left until the solidification of the mass takes place. As soonas a fresh mold-box has been placed into the casing and the latterhermetically closed and again connected with the drum a fresh stonecaube produced. The solidification of the mass, owing to the action of thechemical combination of the substances employed, takes place under thedevelopment of a considerable temperature of say, 212 to 270 Fahrenheit,thereby facilitating the drying of the mass. Lastly, a rising of themass cannot, however, take place, as no air is shut Having now describedand ascertained the nature of myinvention and the manner of carrying thesameinto effect, be it known that what I consider novel, and desire toprotect by Letters Patent, is-

In an improved apparatus for the manufacture of artificial stone free ofpores, from a mixture of burnt magnesite, calcium carbonate and a lye ofmagnesium chlorid as moistening means, from which latter the impuritieshave been removed by submitting to atmospheric air, whereby the saidimpurities settle down and, in consequence of the extraction of thesalts, a consistent and unvariable product is obtained, especiallysuitable for lithogra jihic stones, the combination of ahermetically-closable drum ct, mounted rotatably, containingmixing-balls and provided with moistening means f and g, an opening 0 inthe drum, a funnel b thereabove for the charge of the drum, ahermetically-closable mold-casing h containing a mold-box l and aconnecting-piece between the mixing-drum a and the casing it, thisconnecting-piece being provided with a telescopically-extending pipe7t", adapted to slide into the union d of the mixing-drum in such mannerthat the said drum a and the casing h become hermetically connected,whereby after exhaustion of the air, for instance by means of aninjector or the like, no more air can again enter through theconnecting-piece 7.1 and the production of the stone is effected inuncuo, essentially as and for the purpose set forth.

In witness whereof I have hereunto set my signature in presence of twowitnesses.

FRIEDRICH MARX. lVitnesses:

Monitrz HORN, FRANZ MULLER.

